Earth

+Earth is the home of Humanity. It has never been seen directly in the Subnautica series, though details about the state of the planet can be gleaned from various databank entries. In general, Earth in the Subnautica universe shares the same history as reality, but by 2181 (when the original Subnautica takes place), significant changes have occurred.+ +The Alterra Corporation is named for Earth, with the name "Alterra" literally translating to "by Earth".+ +## Background+ +At some point around the 13th century (1200s), the Architects visited Earth and took a sword that had apparently been used to kill at least seven significant heads of state during that period. It is possible they visited Earth on multiple other occasions, as the Translation Device contains data on multiple ancient Earth languages. The databank entry for the Alien Carving posits that the Architects may have visited Earth prior to the 4th century BC.+ +Prior to The Expansion, humanity remained focused around Earth. However, with the invention of Fabricator technology and Phasegates, it became practical—and perhaps necessary—for humanity to venture further into the galaxy. Nevertheless, humans still live and are born on Earth; for example, Melaku Sansar was born in Kampung Bintang.+ +## Holocene Collapse+ +At an unspecified point prior to the games, Earth experienced the **Holocene Collapse**, an event during the Holocene epoch that resulted in the extinction of a huge number of species. Nahema mentions Earth in the databank entry *"We must voluntarily die"*, stating: "We have never been a worthy steward of any world. We failed Earth, so we fled to the stars," likely influenced in large part by the Holocene Collapse.+ +Species mentioned to be extinct as a result include:+ +*   **Dolphins**: As observed in Earth dolphins before their extinction, this creature seems to understand the concept of other minds, a prime indicator of true sentience.+*   **Cephalopods**: At least 800 species. This trait was present in Earth cephalopods, but its function was not determined before the Holocene collapse.+*   **Stony Coral (Acropora)**: At least 120 species. The gross morphology is a branching tree, like some species of Earth's extinct Acropora.+*   **Soft Coral (Leptogorgia virgulata)**: Named for the extinct Leptogorgia virulata, Earth’s sea whip.+*   **Calcareous Sponges**: Around 700 species. This sponge is chambered, akin to Earth's extinct sphinctozoans.